S-COM 7K - Command Response Messages; Acknowledgment; Errors

7K • Chapter 3
3-4
• The security password in this example is 99, the default password. The
password tells the controller that you are a legitimate programmer.
• The root number is 63. This root number tells the controller that you wish to
control a software switch.
• The 00 specifies the switch, in this case it is the Transmitter 1
Enable/Disable switch.
• The data digits is 0. In this particular command, the 0 tells the controller to
disable transmitter 1.
• The terminator is “*,” which tells the controller that you have reached the
end of this particular command. The controller always waits for the
terminator before it processes a command.
If we make no mistakes in entering this command, the controller will respond
with a message, and turn OFF Transmitter 1. If a mistake is made in the
command, such as a data digit of 2, the controller will send an Error Message,
and Transmitter 1 will not change. If you enter a control command with an
incorrect password or a non-existent root number, the controller will not
respond to the command.
Command Response Messages
Acknowledgment
Most Control Commands respond in some way to tell you that they were
accepted by the controller, or that you made a mistake in entering the
command. The usual Acknowledgment Message is OK (sent in CW). If another
response is more appropriate, a different acknowledgment will be sent instead
of the OK.
Errors
When a mistake is made entering a command, an error message (error) is sent
in CW. There are two commonly-used error messages:
• ? err 1 means you have made an error in the number of keystrokes entered
for a particular command. If the command requires 5 keystrokes, for
example, and you entered 6, the response will be an error 1.
• ? err 2 means you have made an error in the data presented for a particular
command. If a timer, for example, has a range of 0 to 5.0 seconds, and you
entered 6.0 seconds, the response will be an error 2.
Command Response Messages can be turned ON and OFF using the
Enable/Disable Command Response Messages command on page 11-2.